The invention relates to herbicidal and insecticidal spray application and, more particularly, to a trailer or truck mounted sprayer for performing multiple spraying applications.
Numerous problems exist for farmers in the tasks of pest and weed control. Farmers must broadcast herbicides and insecticides at a uniform rate over entire fields for acceptable results. During spraying, the uneven terrain of some fields should be closely contoured to insure correct rates of chemical are applied. Spraying too high above the ground causes the spray pattern to overlap, causing some areas to receive too much chemical, which may "burn" the crops, while others receive too little, allowing weed or insect survival. Carrying the boom too close to the surface being sprayed prevents the full spray target pattern from being realized and results in gaps in coverage where undesirable vegetation or insects may thrive.
Herbicides and insecticides seldom work perfectly. Once crops have emerged, weeds and brush also emerge in some scattered locations or over the entire field. Mechanical cultivation cannot eradicate weeds growing directly in the rows without also destroying the crop. Surviving weeds may be of varying heights and often outgrow the crops, shading them and robbing nutrients from the soil, resulting in lowered crop yields. The current practice is to hand remove these surviving weeds or to manually spot spray with herbicides, both slow and expensive procedures. Alternatively, large areas may be sprayed from a fixed boom height, wasting chemicals and resulting in uneven coverage, as previously described, because of the wide range of weed heights. Also, many fences and ditches are infested with brush which can only be removed by mowing, hand cutting or hand spraying, all uneven and slow processes at best.
Accordingly, it is among the several objects of this invention to provide fully automated accurate broadcast spray capability, automated spot spraying of weed infested fields, simplicity of design and ultimately of maintenance, and a means of spraying fencelines and ditches all without the operator having to leave his seat.
In furtherance of the objects of the invention, it is intended that the invention be trailer mounted, tractor towed and powered, or alternatively, self-propelled and completely self-contained. A tractor drives a hydraulic pump which in turn powers a conventional spray pump and energizes the hydraulic cylinders used for all boom movements. The tractor's electrical system is used to activate all hydraulic and spray valves. Spray nozzles, spray lines, valves and storage tanks may all be commercial models commonly in use.
A further object of the invention is that the sprayer utilize a dual boom arrangement, each boom connected by a boom pin at one end and supported on an air or steel spring at a point along its length. Each boom is hinged between its base section and its mid-section to allow horizontal movement. This permits folding alongside the apparatus for transport or to yield if the boom strikes an immovable object, thereby preserving the integrity of the boom. The boom tip section selectively tilts or rotates vertically to allow folding over the mid-section for transport or below horizontal to permit the boom to contour the terrain being sprayed. A vertical hydraulic pressure-relief valve (or break-away) is used to prevent damage to the boom if the tip comes in contact with the ground or some other fixed object, by allowing the tip to tilt away from the object. An air or steel spring suspension system absorbs shock without transmitting it to the boom.
Another object of the invention is that the twin lateral booms can move independently of each other to permit more accurate contouring of the terrain. Tip sections are optionally used in a vertical position for spraying fences or treelines and various spray widths can be obtained by folding one or more boom sections out of the way.
Both lateral booms are raised or lowered simultaneously by means of pairs of tiltable support arms mounted on the sprayer frame. Parallelogram linkage of the support arms to the lateral spray booms and to the upright support means maintains a vertical spray pattern throughout the full range of height adjustments. All boom movements, including raising the trailing support arms, are intended to use hydraulic power and can be made while the sprayer is in use, without stopping the machine and without the operator leaving his seat.
It is intended that in the broadcast mode the apparatus may spray a width of over 60 feet. Spray height may be adjusted from near ground level to nine feet above the ground. Even greater heights are optionally available for special applications. Sections of the two booms may move vertically or horizontally, as previously described, but independently of movements of the other boom. Each boom rides on an air or steel spring cushion to absorb shocks when the trailer wheels pass through ditches or over uneven terrain. When the boom strikes immovable objects it breaks away hydraulically to prevent damage to the boom. The operator then returns the boom to the spraying position by activating the boom hydraulic system. There is no need for dismounting or stopping to store the boom for transport, to contour the boom to fit the terrain or to change the boom height.
A further object of the present invention is that spot or broadcast spraying over very large weeds, brush, and even trees is possible. In furtherance of this object, the two booms can be raised or lowered to apply contact herbicides for eliminating undesirable vegetation from growing crops. Individual spray nozzles can be activated to spray only a single site or multiple nozzles can be activated for various width broadcast patterns. The ability to quickly raise or lower the booms while in motion enables the operator to place the spray nozzles the correct distance from the plants to be sprayed. Previously, uneven weed heights were a problem because of the need to mechanically raise the boom. The availability of rapid hydraulic changes gives increased crop production by increasing spraying accuracy.
Unlike existing sprayers, the present invention is comprised of two booms each secured by a pin at one end and suspended over an air or steel spring shock absorber, providing a more stable spray platform. Furthermore, the range of spraying heights is greater than present sprayers and can be hydraulically adjusted while the apparatus is in motion. A unique parallel arm system maintains a vertical spray pattern throughout spray boom height adjustment. The sprayer can be folded for transport or unfolded for field use without time-consuming operator dismount. Also, the boom is vertically adjustable to contour uneven ground and various spray widths are possible, from spot to full width, by merely automatically activating various patterns of spray nozzles and folding boom sections. Thus, the sprayer provides added versatility for spraying fences, ditches, etc. Additionally, more efficient use of chemicals is possible with better spray control, more effectively killing weeds or pests and permitting increased crop production. Finally, by having an all-encompassing control console at the tractor, the operator is able to simultaneously control all spray functions and boom movements without dismounting.
Briefly, a vehicular apparatus for spraying herbicides and insecticides comprises the present invention. The apparatus has a supporting frame for being carried by a truck or trailer. Upright supports are carried by the frame and trailing boom supports extend rearwardly from the upright supports. The upright supports carry means for providing selective pivoting of the trailing boom supports relative to the upright supports, for providing vertical adjustability of the spray. Lateral booms are supported by the trailing boom supports and connected to them by means which allow selective pivoting of the lateral boom means relative to the trailing support means as well as to the ground. The lateral booms include a supporting base section, a mid-section, and a boom tip section. At least the tip section, but more preferably, all of the sections, of the lateral boom include spray nozzles for selective spraying of liquids. A pivotal connector connects and provides forward and backward horizontal pivotal movement of the boom mid-sections relative to the boom base sections. Another pivotal connector connects and provides vertical pivotal movement of the boom tip sections relative to the boom mid-sections. The pivotal connectors provide selective horizontal and vertical lateral boom section positioning as well as approximation by the boom sections of terrain contour to be sprayed Hydraulic cylinders permit the lateral boom mid and tip sections to be operationally maintained at preselected positions. A conventional hydraulic pressure relief mechanism permits release of the pressure and the geometry of the apparatus allows the boom sections to release and rotate freely upon forceful contact with an immovable object.
Other features will be in part apparent and in part pointed out in the following description.